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Actinomycetes are Gram positive bacteria with high G+C content in their DNA and are capable of producing variety of secondary metabolites. Many of these metabolites possess different biological activities and have the potential to be developed as therapeutic agents. The aim of the present study was to screen actinomycetes of various ecological niches in Pakistan for cytotoxic and antitumor compounds. Several water and soil samples were collected from different areas in Pakistan and more than 500 actinomycete isolates were recovered by selective isolation techniques. Among them 120 isolates were selected on different morphological basis for identification and cytotoxicity. These isolates were identified on the basis of their Microscopy (Scanning electron microscopy), morphological, biochemical and physiological behavior's along with genetic characterization. The isolates such as MKA 17, SSA 13 and KML 2 showed highest mortality rate with having 92%, 84% and 84% dead larvae (Artemia salina) after 24 hours respectively. Theses potent isolates were tested against proliferative cell lines by Methyl Thiazolyl Tetrazolium (MTT) bioassay method. Isolate KML 2 and SSA 13 showed highest antitumor activity with having IC50 values of 12.17μg/ml and 16.4 μg/ml against HeLa cell line respectively. Chemical screening profile by TLC and robust UPLC-MS showed distinctive chemical diversity in the extracts of selected isolates. Indeed, preparative screening of isolated actinomycetes strains delivered bioactive compounds including actinomycin D and resistomycin from SSA 13 and MKA 17 respectively. The genetic characterization by 16S rRNA gene sequencing exhibited maximum genetic similarity with different species of the well-known genus of actinomycetes named as Streptomyces. [ABSTRACT FROM AUTHOR]

This study was conducted to carry out the qualitative analysis of drinking water system of Lahore, Pakistan to detect the presence of Escherichia coli O157. Potable water samples were collected from different localities and analyzed by the most probable number tests (MPN). Initially, 42 strains that showed morphological resemble with E. coli were characterized by growing on Eosine Methylene Blue (EMB) agar. Finally, 13 E. coli strains that were non-sorbitol fermenters were selected and their taxonomic status was confirmed by using RapID™ ONE identification system. Antibiotic sensitivity profiling of selected bacterial strains was also analyzed and majority were found to be resistant against ampicillin, erythromycin and carbenicillin. All sorbitol negative and biochmically identified E. coli strains were then subjected to serological testing using Prolex™ Latex agglutination kit for detection of somatic antigen Le., O157. Positive agglutination was recorded in all sorbitol non-fermenting strains except S7d and S7e indicating the presence of this virulent strain in drinking water supply system. Analysis of biofilm formation revealed that S7d was the most effective either as single or in co-cultures (S2a+S7d) in the presence or absence of FeSO4. In conclusion, the detection of E. coli 0157 from drinking water suggests a possible health threat in terms of diarrheal diseases and renal syndromes to the local community. [ABSTRACT FROM AUTHOR]

A total of fifty-one actinomycetes strains were selectively isolated on glycerol casein KNO3 agar and actinomycetes isolation agar (AIA). The isolates were screened for the production of insecticidal and larvicidal compounds against 3rd instar larvae of mosquitoes Culex quinquefasciatus and Tribolium castaneum (Red flour bettle). The biological screening revealed the metabolites of three isolates exhibit 100% mortality of the tested larvae. In chemical screening by thin layer chromatography (TLC) and HPLC-UV, the crude extracts obtained from the culture broths of these isolates, exhibited an impressive diversity of the chemical constituents. The selected isolates SA-10BC, SA-9K and SA-9L were characterized for their morphological, biochemical, physiological and cultural characteristics and by 16S rRNA gene sequencing. The the selected isolates show maximum genetic similarity with Streptomyces rochei (99%), Streptomyces minutiscleroticus (98%) and Streptomyces phaeoluteigrisseus (92%) respectively. [ABSTRACT FROM AUTHOR]

The article presents a study that investigated the antagonistic ability of an array of 76 endophytic bacterial isolates to biofilm formers. These isolates were obtained from different plant tissues including root, stem and fresh and wilted leaves of various plants in Punjab, Pakistan. The identification of different bacterial species belonging to the genera Bacillus, Pseudomonas, Serratia, Stenotrophomonas and Micromonospora was achieved through the morphological, biochemical and physiological characterization and 16S rRNA gene sequence analysis of the selected endophytic isolates.

The article presents a study that assesses Pichia pastoris (P. pastoris) as recombinant expression for the biologically active form of antimicrobial peptide Hepcidin 20. It states that the study cultivated P. pastoris strains on different medium, wherein its recombinant expressions were confirmed using polymerized chain reaction (PCR). It says that hepcidin content of the strain determined by enzyme-linked immunosorbent assay (ELISA), was subjected to methanol feeding, and was found to increase its hepcidin expressions. It also reveals the antibacterial property of the recombinant hepcidin against Staphylococcus aureus and Bacillus subtilis, which are suggested to be beneficial on body iron homeostasis and other types of juvenile hemochromatosis.